A computer system in which a plurality of LPARs (Logical Partitions) are mounted on a single physical computer and each LPAR is mounted with an OS (guest OS) to enable the plurality of LPARs to drive a plurality of OSs is available for practical use. Also, there is known a migration technique by which, where an LPAR on one physical computer is to migrate to an LPAR on another physical computer in the active state of the OS in a computer system, the OS on the shift destination LPAR accesses the disk accessed by the OS on the shift origin LPAR immediately after the shifting (see Patent Literature 1).
Among different ways of LPAR migration processing, what causes the shift destination LPAR to succeed the state in which the OS is operating on the shift origin LPAR to enable the OS to continue to operate on the shift destination LPAR is known as live migration.